1 /* 2 * Copyright 2012 Red Hat, Inc <mjg@redhat.com> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/init.h> 12 #include <linux/device.h> 13 #include <linux/sysfs.h> 14 #include <linux/io.h> 15 #include <acpi/acpi.h> 16 #include <acpi/acpi_bus.h> 17 18 static struct acpi_table_bgrt *bgrt_tab; 19 static struct kobject *bgrt_kobj; 20 21 struct bmp_header { 22 u16 id; 23 u32 size; 24 } __attribute ((packed)); 25 26 static struct bmp_header bmp_header; 27 28 static ssize_t show_version(struct device *dev, 29 struct device_attribute *attr, char *buf) 30 { 31 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->version); 32 } 33 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL); 34 35 static ssize_t show_status(struct device *dev, 36 struct device_attribute *attr, char *buf) 37 { 38 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->status); 39 } 40 static DEVICE_ATTR(status, S_IRUGO, show_status, NULL); 41 42 static ssize_t show_type(struct device *dev, 43 struct device_attribute *attr, char *buf) 44 { 45 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_type); 46 } 47 static DEVICE_ATTR(type, S_IRUGO, show_type, NULL); 48 49 static ssize_t show_xoffset(struct device *dev, 50 struct device_attribute *attr, char *buf) 51 { 52 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_x); 53 } 54 static DEVICE_ATTR(xoffset, S_IRUGO, show_xoffset, NULL); 55 56 static ssize_t show_yoffset(struct device *dev, 57 struct device_attribute *attr, char *buf) 58 { 59 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab->image_offset_y); 60 } 61 static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL); 62 63 static ssize_t show_image(struct file *file, struct kobject *kobj, 64 struct bin_attribute *attr, char *buf, loff_t off, size_t count) 65 { 66 int size = attr->size; 67 void __iomem *image = attr->private; 68 69 if (off >= size) { 70 count = 0; 71 } else { 72 if (off + count > size) 73 count = size - off; 74 75 memcpy_fromio(buf, image+off, count); 76 } 77 78 return count; 79 } 80 81 static struct bin_attribute image_attr = { 82 .attr = { 83 .name = "image", 84 .mode = S_IRUGO, 85 }, 86 .read = show_image, 87 }; 88 89 static struct attribute *bgrt_attributes[] = { 90 &dev_attr_version.attr, 91 &dev_attr_status.attr, 92 &dev_attr_type.attr, 93 &dev_attr_xoffset.attr, 94 &dev_attr_yoffset.attr, 95 NULL, 96 }; 97 98 static struct attribute_group bgrt_attribute_group = { 99 .attrs = bgrt_attributes, 100 }; 101 102 static int __init bgrt_init(void) 103 { 104 acpi_status status; 105 int ret; 106 void __iomem *bgrt; 107 108 if (acpi_disabled) 109 return -ENODEV; 110 111 status = acpi_get_table("BGRT", 0, 112 (struct acpi_table_header **)&bgrt_tab); 113 114 if (ACPI_FAILURE(status)) 115 return -ENODEV; 116 117 sysfs_bin_attr_init(&image_attr); 118 119 bgrt = ioremap(bgrt_tab->image_address, sizeof(struct bmp_header)); 120 121 if (!bgrt) { 122 ret = -EINVAL; 123 goto out_err; 124 } 125 126 memcpy_fromio(&bmp_header, bgrt, sizeof(bmp_header)); 127 image_attr.size = bmp_header.size; 128 iounmap(bgrt); 129 130 image_attr.private = ioremap(bgrt_tab->image_address, image_attr.size); 131 132 if (!image_attr.private) { 133 ret = -EINVAL; 134 goto out_err; 135 } 136 137 138 bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj); 139 if (!bgrt_kobj) { 140 ret = -EINVAL; 141 goto out_iounmap; 142 } 143 144 ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group); 145 if (ret) 146 goto out_kobject; 147 148 ret = sysfs_create_bin_file(bgrt_kobj, &image_attr); 149 if (ret) 150 goto out_group; 151 152 return 0; 153 154 out_group: 155 sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group); 156 out_kobject: 157 kobject_put(bgrt_kobj); 158 out_iounmap: 159 iounmap(image_attr.private); 160 out_err: 161 return ret; 162 } 163 164 static void __exit bgrt_exit(void) 165 { 166 iounmap(image_attr.private); 167 sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group); 168 sysfs_remove_bin_file(bgrt_kobj, &image_attr); 169 } 170 171 module_init(bgrt_init); 172 module_exit(bgrt_exit); 173 174 MODULE_AUTHOR("Matthew Garrett"); 175 MODULE_DESCRIPTION("BGRT boot graphic support"); 176 MODULE_LICENSE("GPL"); 177